Metals or metalloids of primary importance to this study are cadmium and selenium. These nuclei are ideally suited for a multinuclear magnetic resonance study involving direct observation of the metal nucleus by Fourier transform techniques because of their respective receptiveness to an nmr experiment and because they are spin 1/2 nuclei. The principal objectives of this project can be divided into two broad categories. First, we will be involved in detailed studies of the mode of interactions of cadmium with metalloproteins. The systems of particular interest to us here are cadmium substituted concanavalin-A, bovine superoxide dismutase, and carboxy-peptidase-A. Secondly, a study of the utility of 77Se nmr in biological systems will be initiated. The proposed 77Se nmr research is further subdivided into three areas of interest. These areas include: (1) the elucidation of the mechanism of the oxidation of sulfhydryl groups by selenium compounds, (2) an effort to clarify the metabolic interactions of selenium with other elements of ecologic concern, i.e. cadmium, mercury, and arsenic, (3) a general survey will be conducted of the molecular identity of selenium within accumulator plants and various bacteria.